Watch Art Cashin: Why I'm a 'little anxious' now

Art Cashin says he's a "little anxious" right now due to the widespread expectation that stocks will rebound sharply, perhaps by 2 to 3 percent, once the Washington stalemate is resolved.

Cashin, UBS' director of floor operations at the NYSE, told CNBC's Bob Pisani around midday that "everybody, particularly in the watering holes of Wall Street ... everybody is talking about how this is a buying opportunity."

To Cashin, that's a contrarian warning signal. "You get uncomfortable in crowds. As Warren Buffet said, 'When people are fearful it's OK to be greedy. But when they're greedy you should be fearful."